Rack supporting device for vehicle steering systems

Abstract

A rack supporting device for vehicle steering systems includes: a steering housing having a steering gear installed therein; a rack bar longitudinally inserted into the steering housing to engage with the steering gear; a tapered passage defined in an inner circumference of the steering housing, wherein the tapered passage is eccentric with an axial center of the steering housing; a rack bushing inserted between an inner circumference of the tapered passage and an outer circumference of the rack bar so that the rack bushing moves along the tapered passage and pushes the rack bar to the steering gear; and an elastic member mounted to one side of the tapered passage to provide an elastic pressing force for pushing the rack bar to the rack bushing.

What is claimed is: 
     
       1. A rack supporting device for vehicle steering systems, the rack supporting device comprising:
 a steering housing having a steering gear installed therein; 
 a rack bar longitudinally inserted into the steering housing to engage with the steering gear; 
 a tapered passage defined in an inner circumference of the steering housing, wherein the tapered passage is eccentric with an axial center of the steering housing; 
 a rack bushing inserted between an inner circumference of the tapered passage and an outer circumference of the rack bar so that the rack bushing moves along the tapered passage and pushes the rack bar to the steering gear; and 
 an elastic member mounted to one side of the tapered passage to provide an elastic pressing force for pushing the rack bar to the rack bushing. 
 
     
     
       2. The rack supporting device of  claim 1 , wherein one wall of the tapered passage facing a back surface of the rack bar is thicker than the other wall of the tapered passage facing a front tooth surface of the rack bar. 
     
     
       3. The rack supporting device of  claim 1 , wherein the rack bushing has an outer circumference that is formed of a tapered surface configured to come into contact with the tapered passage. 
     
     
       4. The rack supporting device of  claim 3 , wherein the tapered surface is in contact with one wall of the tapered passage facing a back surface of the rack bar. 
     
     
       5. The rack supporting device of  claim 1 , wherein the rack bushing has an inner circumference that is formed of a rectilinear contact surface pressed against a back surface of the rack bar to push the rack bar to the steering gear. 
     
     
       6. The rack supporting device of  claim 1 , wherein a liner is inserted into an inner circumference of the rack bushing to reduce friction with the rack bar. 
     
     
       7. The rack supporting device of  claim 1 , wherein the elastic member is a Belleville spring. 
     
     
       8. The rack supporting device of  claim 1 , wherein a plug is fixedly mounted behind the elastic member in the steering housing to prevent separation of the elastic member and the rack bushing. 
     
     
       9. The rack supporting device of  claim 8 , wherein the plug has a through-hole formed at its center so that the rack bar passes through the through-hole, and wherein the plug has a male thread formed on its outer circumference so that the male thread is fastened to a female thread formed on the steering housing. 
     
     
       10. The rack supporting device of  claim 9 , wherein the through-hole of the plug has a hexagonal shape to insert a screw fastening tool thereinto.